It is known to provide a blind spot detection/LCA system for a vehicle that detects the presence of another vehicle or object in the lane next to the host vehicle, where it may be difficult for the driver of the host vehicle to determine whether or not there is another vehicle or object adjacent to the host vehicle. Such a blind spot detection/LCA system often includes a visual indicator that visually indicates to the driver that another vehicle or object has been detected. The visual indicator (commonly a light emitting diode or the like) is often located at the reflective mirror element of the exterior rearview mirror assembly and external of the vehicle cabin, or may be located interior to the vehicle, such as at the A-pillar of the vehicle within the interior of the vehicle cabin (such as on MY 2005 Volvo vehicle models equipped with camera-based BUS systems). The visual blind spot/LCA indicators indicate or alert to the driver of the host vehicle the presence or impending presence of another vehicle in a blind spot in an adjacent side lane that typically cannot be readily seen within the field of view of the exterior mirror reflective element of the exterior mirror assembly mounted at that side of the vehicle and/or cannot be readily seen by the driver's peripheral vision or the like. The visual blind spot/LCA indicators typically must be viewable principally or solely by the driver of the host vehicle and not by drivers of other vehicles. If the indicator is located external to the vehicle cabin, and especially since it is now common to use turn signals on exterior mirrors, any visibility of the indicator to the driver of another vehicle (such as a trailing vehicle or an overtaking vehicle) may cause confusion to the driver of the other vehicle as to whether or not the indicator is a turn signal indicator or some other vehicle lighting or the like. This may be particularly problematic when the blind spot indicator is located behind (and often supported by) the reflective mirror element of the vehicle exterior mirror assembly, and may be especially confusing if other indicators are also disposed behind/supported by the mirror reflective element so as to function, for example, as turn signal indicators. For example, somewhat costly and complicated blind spot indicator constructions have been contemplated that, when placed behind and supported by the mirror reflective element, attempt to have their projected beam of emitted light shielded from view by other drivers and attempt to be directed principally to be viewed by the driver of the host vehicle. This can be further complicated by the fact that the mirror reflective element (and hence any blind spot indicator supported thereon/therebehind) is adjustable via a mirror actuator (such as described in U.S. Pat. Nos. 6,755,544; 6,616,314; 6,467,920; and 6,243,218, which are hereby incorporated herein by reference in their entireties), so that the axis of principal illumination of the blind spot indicator will move with movement of the mirror reflective element.
Thus, prior art blind spot/LCA indicators are often supported by and to the rear of the movable mirror reflective element, so as to be viewable by a driver of the host vehicle through the reflective element of the mirror assembly. For example, a transmissive window may be formed in the reflective coating or coatings of the reflective element and an illumination source or indicator may be positioned so as to direct or emit illumination through the window and toward the driver of the host vehicle so as to be viewable by the driver of the host vehicle. Alternately, transflective mirror coatings (such as, for example, those described in U.S. Pat. Nos. 6,855,431; 5,724,187; 5,340,503; 6,286,965; 6,196,688; 5,535,056; 5,751,489; and 6,065,840, which are hereby incorporated herein by reference in their entireties) may be used.
Because of vehicle regulations and mirror and vehicle configurations and geometries, and because of the need to provide an uninterrupted reflective surface to satisfy the likes of the FMVSS 111 field of view regulation, blind spot/LCA indicators in the prior art are typically located towards or at the outboard edge, and typically towards or at the upper corner/quadrant, of the reflective mirror element of the exterior mirror assembly. Thus, the prior art blind spot/LCA indicators are located at a distal or furthest outboard location of the mirror reflective element, such that the driver of the host vehicle typically has to look across to the outboard dimension of the reflective element to view and discern the blind spot indicator. Also, the blind spot/LCA indicators (when located at the reflective element so as to be viewable through the reflective element and when supported thereon such that the blind spot/LCA indicator moves in tandem with the mirror reflective element when its field of view is adjusted by the driver to his/her preferences) may be directed differently for different drivers. These prior art blind spot/LCA indicators thus are not provided at a universally controllable angle or fixed angle relative to the geometry of the vehicle and thus may not be optimally directed for viewing by some drivers, depending on the desired and set angle of the mirror reflective element for the particular driver of the host vehicle and/or may not be optimally directed for non-viewing by drivers of other vehicles, such as trailing or overtaking vehicles that are part of the traffic encountered by the host vehicle.
A variety of interior and exterior mirror assemblies with indicators are known in the art, such as U.S. Pat. Nos. 5,788,357; 6,257,746; 6,005,724; 5,481,409; 6,512,624; 6,356,376; 2,263,382; 2,580,014; 3,266,016; 4,499,451; 4,588,267; 4,630,904; 4,623,222; 4,721,364; 4,906,085; 5,313,335; 5,587,699; 5,575,552; 5,938,320; and 5,786,772, Canadian Pat. No. CA 1,063,695, Pat. Abstracts of Japan Publication No. 0917573, published Jul. 8, 1997, which are all hereby incorporated herein by reference in their entireties.
Therefore, there is a need in the art for an improved blind spot/LCA indicator that is readily viewable by a driver of the host vehicle and not visible or viewable by a driver of another vehicle.